1. Field of the Invention
The present invention relates generally to semi-automatic firearms, and more specifically to barrels and takedown levers for semi-automatic firearms.
2. Discussion of the Related Art
Some semiautomatic pistols utilize a short-recoil mechanism, where both the barrel and slide move together rearward upon discharge of the firearm. Prior to firing of the cartridge, the barrel is engaged to the slide by a locking mechanism, in some embodiments including a locking block. After firing, the recoil force drives both the barrel and the slide rearward, but since they are in engagement, the extraction of the casing has not started. After the initial recoil period has passed, an actuator (in some embodiments an upper projection of the locking block that engages with a portion of the barrel) begins to disengage the barrel from the slide. The rearward movement of the barrel is arrested, while the slide continues rearward and begins extraction of the casing using its kinetic energy and the residual gas pressure in the barrel. The slide continues until full rearward travel is reached.
Modern semi-automatic firearms may include a takedown lever. One use of the takedown lever is for assembling and disassembling the firearm. In one position the takedown lever prevents removal of the slide assembly, but when the takedown lever is manually positioned out of the retention position the slide and barrel assembly are removable without tools.
In some firearm configurations, the takedown lever is also involved in the firing process. In some takedown lever designs, the internal portion of the takedown lever can interact with the barrel during the firing process. The interaction between the takedown lever and the barrel during firing may cause the barrel to skew out of alignment during firing, adversely affecting the accuracy of the firearm. Additionally, the interaction may cause the barrel to drop out of battery after firing.